Cruise control systems for vehicles include a following control system that selects as the leading vehicle one of the vehicles traveling ahead of the own vehicle that is on the same lane as the own vehicle, and controls the own vehicle so that it follows the selected leading vehicle. For such following control, accurately selecting a vehicle traveling on the own lane from the vehicles detected by a distance sensor, a vehicle mounted camera, or the like is important. In a conventional technique, the future path the own vehicle is predicted to take is calculated using operations, and a vehicle in the predicted path is set as the target leading vehicle of the following control. For example, PTL 1 discloses a method for selecting the target leading vehicle of the following control as follows. In the technique disclosed in PTL 1, first, a turning circle is calculated based on the yaw rate and the vehicle speed as a prediction of the path which the own vehicle is going to take. Then, in the technique disclosed in PTL 1, the own lane probability, which is the probability of a vehicle ahead of the own vehicle being on the own lane, is calculated based on the lateral offset distance between the course of the own vehicle and the lateral position of the vehicle ahead of the own vehicle. In the technique disclosed in PTL 1, the leading vehicle to be followed is selected according to the calculated own lane probability.